Environmental Biotechnology Division, School of Biosciences and Technology, VIT University, Vellore, 632 014, Tamil Nadu, India.
Biodegradation. 2011 Nov;22(6):1181-9. doi: 10.1007/s10532-011-9473-1. Epub 2011 Apr 3.
The performance of diesel oil degradation by Candida tropicalis immobilized on various conventional matrices (sodium alginate, carboxyl methyl cellulose, chitosan) and biowaste materials (wheat bran, sawdust, peanut hull powder) was investigated using the method of entrapment and physical adsorption. The yeast species immobilized in wheat bran showed enhanced efficiency in degrading diesel oil (98%) compared to free cells culture (80%) over a period of 7 days. Copious amount of exopolysaccharides were also produced in the presence of diesel oil. The biofilm forming ability of C. tropicalis on PVC strips was evaluated using XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) reduction assay and monitored by scanning electron microscopy and atomic force microscopy. Yeast biofilm formed on gravels showed 97% degradation of diesel oil over a period of 10 days. The potential use of the biofilms for preparing trickling filters (gravel particles), for attenuating hydrocarbons in oily liquid wastes before their disposal in the open environment is suggested and discussed. This is the first successful attempt for 'artificially' establishing hydrocarbon degrading yeast biofilm on solid substrates.
采用包埋法和物理吸附法研究了固定在各种常规基质（海藻酸钠、羧甲基纤维素、壳聚糖）和生物废料（麦麸、木屑、花生壳粉）上的热带假丝酵母对柴油降解的性能。与游离细胞培养（80%）相比，在 7 天的时间内，固定在麦麸中的酵母物种在降解柴油方面表现出更高的效率（98%）。在柴油存在的情况下，还产生了大量的胞外多糖。使用 XTT（2,3-双[2-甲氧基-4-硝基-5-磺苯基]-2H-四唑-5-羧酰胺）还原测定法评估了 C. tropicalis 在 PVC 条上形成生物膜的能力，并通过扫描电子显微镜和原子力显微镜进行了监测。在砾石上形成的酵母生物膜在 10 天内将柴油降解了 97%。建议并讨论了将生物膜用于制备滴滤器（砾石颗粒），以及在将油基废液排放到开放环境中之前用于衰减烃类物质的潜在用途。这是首次在固体基质上“人为”建立烃类降解酵母生物膜的成功尝试。
